1. Field of the Invention
The present invention relates to hand manipulated exercise devices and more particularly, to a device including opposed tubes, one telescopically received in the other, which are rotatable in opposite directions with the rotation being frictionally resisted in an axial direction by means of pressure on opposite sides of a rubber washer in the tubes. The degree of frictional resistance to rotation is adjustable utilizing a special indicator wrench.
2. Description of the Prior Art
Heretofore, various hand manipulatable exercise devices have been proposed. Examples of such previously proposed devices are disclosed in the following patents:
______________________________________ U.S. PAT. NO. PATENTEE ______________________________________ 3,184,234 Struble 3,211,453 Williams 3,666,267 McKinney 3,717,338 Hughes 3,764,131 Rooks 3,830,493 Miller 4,095,789 Mueller 4,155,547 Savio et al 4,171,802 Stoecker ______________________________________
The Struble U.S. Pat. No. 3,184,234 discloses an exercise device for use in developing the muscles of the hands, wrist and arms. The invention comprises a pair of generally cylindrical hollow gripping elements rotatably mounted in end to end relation on a rod. Disc-like friction members are situated adjacent axial end faces of the gripping members and a retainer member in the form of a knob is mounted on each terminal end of the rod. At least one of the knobs is adapted for movement axially on the rod whereby the pressure applying relation between the gripping elements and the friction member may be varied selectively, thereby to vary the resistance to relative turning of the gripping elements to suit the exercise requirements of the user.
The Williams U.S. Pat. No. 3,211,453 discloses a hand, wrist and arm exerciser embodying a pair of companion end-to-end axially aligned hand grips. One grip is provided for each hand, and each grip being appropriately shaped and contoured for retention in the hand. These two grips are coupled in axial alignment, each have a tubular casing with contiguous inner ends being plugged and the plugs being disposed in abutting relationship and relatively movable one in relation to the other by turning of the hand grips in opposite rotatable directions. A brake assembly is positioned in one hand grip while the other hand grip is provided at an outer end with a finger turn knob, the knob serving to actuate a brake operating rod and the rod being arranged with one end portion connected to the brake assembly, and the other end portion adjustably and operatively connected to the knob.
The McKinney U.S. Pat. No. 3,666,267 discloses an exercising device for the hands, wrist and forearm including an elongate bar having an enlarged flange integral with one end thereof. An enlarged rotatable member is carried at right angles to the bar in frictional contact with the flange. A friction producing member is carried between the flange and the rotatable member and forces exerted by the hands with respect to the rotatable member are resisted by the engagement thereof with the friction producing member. A spring is provided with a compression adjustable mechanism for varying the frictional contact force between the flange and the rotatable member.
The Hughes U.S. Pat. No. 3,717,338 discloses a wrist exercising device comprising two hand grip units provided with adjacent friction surfaces compressed together by a spring. The pressure exerted thereby is adjustable by a threaded rod screwed in one of the units to which the spring is connected. The spring is also connected to an adjusting knob on the other unit whereby spring tension is adjusted by turning the knob to move the rod.
The Rooks U.S. Pat. No. 3,764,131 discloses a wrist exerciser comprising a pair of slightly conical, hollow, and substantially identical, hand grips which are sleeved at their adjacent ends snuggly upon the opposite ends of a connecting member for relative rotation. Nut and bolt members extend lengthwise within the grips and engage transverse wall sections within the grips for adjusting the frictional engagement of the grips with the connecting member. Additional larger and hollow hand grips can be mounted upon the smaller hand grips to increase the diameter of the manually grippable surfaces.
The Miller U.S. Pat. No. 3,830,493 discloses a hand and wrist exercising device including a pair of generally cylindrical hand grippable elements coaxially mounted for relative rotation and having opposite radial end faces with an annular rubber disc disposed between and engaging the opposite radial end faces to resist relative rotation between the elements. One of the elements has an axial bore and a shaft extends through the bore and has one end fixed to the other element and a cap threaded on the other end. A helical compression spring is mounted around the shaft within the bore and acts between a shoulder in the bore and the cap through a thrust bearing so that the spring exerts a force biasing the hand grippable elements toward one another against the rubber disc. The amount of friction is varied by turning the cap on the shaft to adjust the spring compression and thereby the biasing force.
The Mueller U.S. Pat. No. 4,095,789 discloses a torsional twist, wrist exercising device including a pair of hand grips disposed in contiguous end-to-end relation on a common central longitudinal axis. The grips are operatively interconnected with each other so as to maintain their contiguous relation while permitting rotative movements thereof relative to each other about their common axis. A central longitudinally extending shaft is affixed at one end to one of the grips and a central longitudinal bore is formed within the other grip for coaxially receiving the shaft. At least one torsion spring is supported upon the shaft and spring retaining members are provided for detachably securing one end of the spring to the shaft and the other end of the spring to the wall defining the interior surface of the bore. A cap member is provided for maintaining contiguous end-to-end relation of the grips during exercising use.
The Savio et al U.S. Pat. No. 4,155,547 discloses a torsion spring type wrist exercising device comprising a pair of longitudinally aligned tubular members movable axially relative to each other, such movement being resisted by an adjustable spring force. A spring system has a variable length to adjust the tension and the torsion of the spring system. One of the tubular members is preferably formed of a clear material in order that the adjustment can be visually observed.
The Stoecker U.S. Pat. No. 4,171,802 discloses a hydraulic torque reaction wrist and arm exerciser employing rotary motion and including a resistance torque device with first and second relatively rotatable units mounting hand grips. The units are spaced substantially equa-distance between the hand grips. Resistance torque is developed within the device upon rotating the hand grips. The amount of torque is determined by the restriction of flow of hydraulic fluids between compartments of an annular chamber increasing in proportion to the turning effort applied to the device and being adjustable by an externally operable valve mechanism for changing the size of the flow restriction, one of the units having a mechanism for restricting fluid movement therefrom.
As will be described in greater detail hereinafter, the hand manipulated exercise device of the present invention differs from the devices previously proposed by being simpler to manufacture and assemble than prior exercising devices and by providing for fixing of a spring tension assembly within one tube of the device such that the spring of the assembly rotates with the tube when the tube is rotated thereby eliminating wear on the surfaces of washers against which ends of the spring bear.
The device of the present invention further includes a special indicator wrench for adjusting the degree of frictional resistance to rotation between the opposed handles of the device and for indicating the amount of frictional resistance being employed.